UU: now imagine that not only does the Universe exist inside it, depending on the creature’s health and well being to survive…
UU: but every potential instance of that Universe exists inside as well.
UU: those that are doomed and those with promise.
UU: even those that were reset from scratch, with slightly different starting conditions.
UU: all of those interrelated Universes mingling together inside your frog, inextricable from its physiology.
UU: if the frog dies, they all go with it. eventually.

You saw her looking at the page in Rose’s book that was scribbled on, yes?
We know that that was Dave and Karkat, but she freaks out for a minute and thinks that her brother was somehow involved in all that. Then, keeping in mind her appearance (and thus her brother’s appearance) and the fact that Gamzee redacted Lord English’s name from the book and thus from her knowledge, it seems pretty clear to me.

Holy crap I just realized something. English has a prosthetic leg. He cut off his leg to get out of the shackle thing.